1. Field of the Invention
The present invention relates to a magnetic tape cassette such as a video cassette.
2. Description of the Prior Art
As shown in FIG. 1, the magnetic tape cassette usually comprises a casing formed by an upper casing (1) and a lower casing (2); reels (4), (5) for winding and running a magnetic tape (3) in the casing; a tape pad (6) in the running path of the magnetic tape (3) between the reels (4), (5) so as to push the magnetic tape (3) by spring pressure of a spring member (6b) between a guide (7) and a tape contacting part (6a) of the tape pad (6), whereby the stable running of the magnetic tape (3) is maintained. In FIG. 1, the reference numeral (8) designates a guide pole.
FIG. 2 is an enlarged view of the structure of the conventional tape pad (6) wherein the tape contacting part (6a) is bonded at one end of the spring member (6b) made of elastic plate and a duplicated adhesive tape (6c) is bonded along the other end of the spring member (6b). One surface of the duplicated adhesive tape (6c) is bonded to the support connected to the lower casing (2) so as to assemble the tape pad (6) in the casings (1), (2).
The spring member (6b) should be made of a substrate having elasticity so as to apply suitable pressure to the magnetic tape (3). The tape contacting part (6a) should be made of a substrate having low friction and low wearing property so as to prevent friction damage of the magnetic tape (3) under the condition applying the spring pressure of the spring member (6b) to the magnetic tape (3). In the conventional structure, the spring membrane is formed by an elastic plate made of polyethyleneterephthalate etc. The tape contacting part (6a) is made of a substrate having low friction and low wearing property such as graphite and polytetrafluoroethylene. They are bonded each other with the duplicated adhesive tape (6d).
Therefore, the conventional tape pads have the following disadvantages.
(1) The spring member and the tape contacting part should be separately prepared and combined whereby the assembling operation is complicate to cause high cost.
(2) The spring member (6b) is bonded to the tape contacting part (6a) with the duplicated adhesive tape (6d) whereby the tacky adhesive of the duplicated adhesive tape (6d) is squeezed from the bonded part and is adhered on the surface of the magnetic tape (3) to cause a trouble for magnetic recording and a trouble for running etc.